Hot Rods Rochester 2brl Loads up

I'm sure there is simple solution this and i have forgotten. 348,tri power. running only on center carb. runs good. until you stop at light. seems to load up pretty bad. Lots of black smoke when i take off? No power. clears up goes again. What am i missing??

 

Float set too high is my guess and do you have a reg set below 3 lb's? Are other carbs sealed off gas lines.?

 

What Dana said.

1. Float set too high.
2. Too much fuel pressure.
3. Idle mixture incorrectly set.
4. Dirt in the needle/seat.

Mike

 

could be a br*** float with a pinhole in it..........

 

Add worn out needle & seat...

 

Stick or automatic? Idle speed correct? Other than that I'm with Dana, float set a tad too high maybe.

 

Are the other 2 carbs totally blocked off as in a plate under the carb on the intake? or are they just unhooked.

 

Covered pretty well, but a few other possibilities:

(1) electronic ignition conversion and still using generator
(2) incorrect orifice in the fuel valve seat (one size may fit all, but it doesn't necessarily work on all)
(3) modern reproduction float (used originals are much more reliable)

Jon

 

Sorry guys ,working 12 hrs. Sleep and work!!! Explain number 1 please. Outer carbs have fuel blocked off but do no have plate under them.

 

You need to plate off the outside carburetors if not in use.

 

If your vehicle is equipped with a generator, and you install an electronic ignition conversion; best result will occur if the generator is upgraded to an alternator. Electronics like a staple voltage. As a general rule, generators can provide sufficient voltage above idle, but insufficient voltage at idle. Have had a lot of customers with "carburetor idle issues" right after an electronic conversion. Engine runs great above idle, but rough at idle speeds.

Just one possibility.

Jon.

 

Interesting Jon, I have not heard or experienced that with a Pertronix and a stock generator. I do check voltage at idle with the lights on and off. Thanks for the information and heads up..

 

When it cools off I’m going to hook them up and run them. .......I hope


Sent from my iPhone using The H.A.M.B. mobile app

 

This sounds more like a failing battery , you would think any ignition would function with 12 volts , even at idle , the battery should maintain 12 volts

 

Perhaps I have made a general ***umption that was too general.

Perhaps a voltage regulator could be causing the problem or a failing battery; but innumerable customers over the years have called with "carburetor idle issues" and we have suggested the upgrade, and many have called back to tell me problem solved. However, they did not tell me if they also changed the battery. So possibly I made an incorrect ***umption.

I still believe it is worth checking.

Jon.

 

I had no idea. Thanks for responding. But there is another issue My car has the generator driven P.S. off the back of generator.I would never even thought to check this. I'll try to the other first, hope they help. save your suggestion for last for the reason of the PS. again many thanks because i absolutely had never heard of this.

 

When I worked at Mazda in the 80's we had a problem with some cars dieing at idle, some times a bigger battery help or raising the idle.Warranty wouldn't pay for that we were trying different things and somebody figured out the air gap in the dist was to wide. The cars all ran fine we started setting air gaps and the problem @ idle went away so I see how low voltage could cause it.

 

If somebody has a scope and checked the KV @ idle?